This invention relates to toothbrushes, in particular to toothbrushes with removable brush heads.
Toothbrushes in common usage comprise a single piece with an elongated handle, typically of plastic, with an integral brush head having a plurality of bristles imbedded therein. When the bristles become worn or bent, as usually happens within a few months, the entire toothbrush is conventionally tossed into the garbage and a new one purchased. This is environmentally unsound because the relatively large amount of plastic in the handle is rarely recycled, but usually ends up adding even more material for landfill sites. Typically the plastic is made of petroleum derivatives, a finite resource.
In addition, it is not really possible to have one brush suitable for all purposes. For example, a softer brush is beneficial in the morning when the gums are more delicate. A more vigorous, that is harder, brush can be used in the afternoon. A medium brush is most appropriate for evening use. Various compromises have been tried including having different hardness of bristles on different portions of the brush head, but a compromise suitable for all times is not really possible. Therefore a person should have several toothbrushes for different proposes. This takes up a lot of space and adds considerable clutter to the washroom, particularly when the washroom must store the toothbrushes of several persons.
Toothbrushes with interchangeable brush heads have been developed in the past. For example, U.S. Pat. No. 5,138,733 to Bock describes an ultrasonic toothbrush with a removable head. The brush head includes a tapered tongue section which is flexible. The brush head has a nose section which incorporates a tapered recess. The brush head may be removed from the handle, but this requires a special tool.
U.S. Pat. No. 2,638,614 to Anderson and U.S. Pat. No. 2,668,973 to Glaza both illustrate toothbrushes with removable heads. In the Anderson Patent the brush head is retained on the handle by a hump which engages a corresponding detent in a finger. In the Glaza Patent the head is retained by a leaf spring which has a rib adapted to engage a notch in the head.
Other relevant patents include U.S. Pat. No. 1,859,425 to Bell, U.S. Pat. No. 2,111,880 to Waters, U.S. Pat. No. 2,228,754 to Cosby, British Patent No. 216,355 and German Patent 2,402,521.
The prior art shows that it is known to construct a toothbrush having a removable brush head and to retain that brush head on the handle with a flexible tongue and detent arrangement. However, removing the brush head from the brush is not always an easy task with the prior art references. In particular, it is not an operation which can be readily accomplished using one hand.
Accordingly, it is an object of the invention to provide an improved toothbrush with a removable brush head where rite brush head can be removed from the toothbrush very easily using only a single hand.
It is also an object of the invention to provide an improved toothbrush with replaceable brush heads which is simple and rugged in construction and economical to produce and market.